This proposal seeks to implement a brief screen for alcohol use disorders (AUDs) among the approximate 6,000 participants in the upcoming 2006 National Highway Safety and Traffic Administration (NHSTA) National Roadside Survey (NRS). There is a body of evidence that purports heavy and problem drinkers are overrepresented in the population of DUI offenders and pose a significant threat to highway and traffic safety. A brief AUD screener validated as rapid roadside assessment of AUDs is proposed for inclusion in the upcoming NRS. This project will clarify the extent to which drivers in general, and more specifically drivers with elevated blood alcohol contents as measured by standardized breath tests have current alcohol problems. If successful, this screen will aid policymakers in determining appropriate intervention services for DUI offenders as well as correlate cross-sectional BAG readings with varying types of pathological alcohol use, namely binge drinking, heavy drinking, and alcohol abuse and dependence (potential signals for unmet treatment need). The alcohol screen proposed for use in this large roadside survey is grounded in existing evidence derived from and exploratory program where the screener was refined, piloted and validated as a rapid roadside screening tool. The measurement constructs to be employed are the consumption subscale of the Alcohol Use Disorders Identification Test (AUDIT) and the Alcohol Use Disorder and Associated Disabilities Interview Schedule (AUDADIS). This work is divided into three distinct phases. Phase 1 entails preparation for the 6,000 case fielding of the NRS. Phase 2 is the fielding of the NRS Program and Phase 3 is dedicated to analysis of data and dissemination of findings. The specific aims of this work are: Aim 1: To assess the extent to which persons with alcohol-use disorders (AUDs) are present in the nighttime weekend driving population, the period of greatest risk for alcohol-related crash fatalities. Aim 2;To conduct an assessment of the relationship between cross-sectional BAG and active AUD status, including adjustment for active other drug use. Aim 3: To identify characteristics of nighttime weekend drivers that signal unmet treatment need for drug- and alcohol-related prevention or intervention services. Health significance: The significance of this work is best viewed in light of the substantial societal resources being allocated to address the perceived risk posed by AUD drivers who are believed to be chronic DUI offenders as evidenced by the passage of state laws. This nationwide probability sample will enable national prevalence estimates of the extent to which persons with AUDs are represented in the most at-risk for crash, injury and death driving and passenger population.